1. Field of the Invention
The present invention is related to a high frequency heating apparatus equipped with an oven hood, which owns a function capable of ventilating gas generated from another heat-cooking apparatus installed under a main body of the own high frequency heating apparatus, and is arranged to convert electric power into high frequency electric power with employment of a semiconductor element.
2. Description of the Related Art
Conventionally, as this sort of appliance, such a high frequency heating apparatus having a construction capable of converting electric power into high frequency electric power with employment of a semiconductor element has not yet been proposed. However, there is merely provided a heating appliance having a ventilation means and an arrangement for supplying high frequency electric power by way of an LC resonant circuit constituted by a heavy weight object. FIG. 7 represents an appliance having the conventional arrangement.
In FIG. 7, reference numeral 1 shows a heating chamber for storing thereinto an object to be heated, reference numeral 2 represents a power supply apparatus having an LC resonant circuit arrangement which heats the object to be heated, and reference numeral 3 shows a ventilation means for ventilating gas generated from another heat-cooking apparatus installed under a main body of the conventional appliance. Also, reference numeral 4 indicates an illumination means for illuminating the above-described another heat-cooking apparatus by using light, which is installed under the main body of this conventional appliance.
Additionally, in microwave ovens corresponding to high frequency heating apparatus, various technical ideas have be taken in order to shorten heating time. For instance, as described in Japanese Laid-open Unexamined Patent Publication No. Hei-2-227988, while peripheral temperatures of the respective elements such as a magnetron are detected, since maximum output power higher than the normal continuous maximum output power is generated for a time period until the detected temperatures reach the safety limiting temperatures of the respective elements, such a technical idea is made that the heating time is shortened while the safety characteristics of the respective elements are secured.
However, in usual homes, these microwave ovens are normally used under the power supply having the rated power of 100V/15A due to the Japanese indoor electric wiring system, so that power consumption of these microwave ovens should be suppressed lower than, or equal to 1.5 KW.
Referring now to FIGS. 16A, 16B, and 16C, power consumption of a microwave oven which constitutes a conventional general-purpose high frequency heating apparatus will be explained.
In FIGS. 16A, 16B, and 16C, an abscissa shows time xe2x80x9ctxe2x80x9d, and an ordinate indicates power consumption xe2x80x9cWxe2x80x9d. FIG. 16A shows an overall power consumption of the microwave oven. Similarly, FIG. 16B indicates electric power xe2x80x9cW1xe2x80x9d which is consumed so as to oscillate electromagnetic waves from a magnetron corresponding to an electromagnetic wave radiation unit employed in the microwave oven. FIG. 16C indicates other power consumption, namely power consumption xe2x80x9c2Wxe2x80x9d of a cooling means (for example, fan), an illumination means (lamp), and a food mounting means (turn table). Although the power consumption xe2x80x9cW2xe2x80x9d shown in FIG. 16C is substantially constant irrespective of a time elapse, the electric power W1 which is consumed so as to oscillate the electromagnetic waves and is represented in FIG. 16B is slightly changed, depending upon temperatures of the magnetron and the control method. In this case, this power consumption W1 is slightly decreased from a stating time xe2x80x9c0xe2x80x9d of the heating operation up to time xe2x80x9ct6xe2x80x9d, and then, becomes constant after this time xe2x80x9ct6xe2x80x9d. Since FIG. 16A is the entire power consumption of the microwave oven, this power consumption becomes xe2x80x9cW1+W2xe2x80x9d. Now, in such a case that general-purpose microwave ovens are employed, these microwave ovens are usually used under the power supply having the rated power of 100V/15A. Thus, the power consumption of these microwave ovens is suppressed lower than, or equal to 1.5 KW. Within this power consumption of 1.5 KW, electric power of the fan (10 W), the lamp (30 W), and the turn table (10 W) is consumed other than the oscillation of the electromagnetic waves. Furthermore, as to the oscillation of the electromagnetic waves, since the actual power consumption is changed into the electromagnetic waves at an efficiency of approximately 50 to 60%, high frequency output power defined from 500 W to 700 W are mainly used so as to heat foods.
However, since the high frequency electric power cannot be controlled in a linear manner in the above-explained conventional appliance as shown FIG. 7, this appliance is designed by that a total value of maximum rated electric power of the respective electric components does not exceed an upper limit value which is determined with respect to entire power consumption of this conventional appliance.
In other words, even when the ventilation means and/or the illumination means are not operated, the total power consumption thereof is not added to the high frequency electric power used to heat the object to be heated. Also, since the power control operation performed when the heat cooking operation is carried out is realized by interrupting constant high frequency output power, the proper high frequency output power cannot be supplied in response to heating conditions of the object to be heated during the cooking operation, which may cause fluctuations in cooking performance to be extended. Furthermore, the LC power supply is a heavy weight object having a weight of approximately 10 KG including a high voltage transformer and a high voltage capacitor. Moreover, in the case that this heavy-weight appliance whose gravity center is considerably deviated qn the side of the electric chamber is installed, installation works thereof are necessarily required by conducting a plurality of workers. Therefore, there is a problem as to a safety characteristic with respect to such an aspect that after the heavy-weight appliance whose gravity center is deviated is installed, since a strength of a wall plane is not sufficiently large, such a heavy weight appliance is not fixed under stable condition.
Futhermore, in the above-explained conventional arrangement, since the power consumption used other than the oscillation of the electromagnetic waves is continuously constant after the heating operation is commenced, there is an upper limit in electric power which is used to oscillate the electromagnetic waves. Therefore, there is a problem that the heating time cannot be shortened.
Also, inversely in order secure a large amount of electric power so as to oscillate the electromagnetic waves, if the cooling means such as the fan is eliminated, then another problem will occur. Namely, reliability of the microwave oven is deteriorated, for instance, the break down of the electromagnetic wave radiation unit such as the magnetron occurs due to the temperature increase. Also, if the illumination means such as the lamp is eliminated, then there is another problem that the progressive degrees of the heating operation cannot be observed outside this microwave oven. When the food mounting means such as the turn table is eliminated, the food cannot be uniformly heated. As a result, there is another problem that the quality of the cooking result is fluctuated.
The present invention has been made to solve the above-described problems of the prior art, and therefore, has an object to provide a high frequency heating apparatus capable of deriving maximum high frequency electric power from a limited power consumption regulating value, capable of deriving cooking performance in maximum, and also capable of largely improving an installation workability of an appliance and a safety characteristic of fixing the appliance after the installation, while providing cooking performance, and either installation performance or safety performance of the appliance, which can be satisfied by customers.
Furthermore, the present invention has been made to solve the above-explained problems, and therefore, has an object to realize a high frequency heating apparatus capable of confirming a progressive degree of heating food, and capable of uniformly heating the food, while heating time is shortened and break down of a magnetron and the like due to a temperature increase does not occur.
To solve the above-described problems of the prior art, a high frequency heating apparatus equipped with a high frequency power control means made of a semiconductor element and an oven hood function, according to the present invention, is arranged to be controlled in such a manner that maximum high frequency electric power can be conducted within an upper limit value of power consumption; high frequency output power can be increased/decreased in a linear manner, if required; and a weight of an appliance can be largely reduced.
As a consequence, highest-speed heat-cooking operation by outputting the maximum high frequency power can be realized, the cooking sequence capable of conducting the optimum cooking performance can be realized, and the installation performance and safety performance of the appliance with respect to the appliance mounting wall plane can be largely improved.
To solve the above-described problems of the prior art, a high frequency heating apparatus equipped with a high frequency power control means made of a semiconductor element and an oven hood function, according to the present invention, is arranged to be controlled in such a manner that maximum high frequency electric power is conducted within an upper limit value of power consumption; high frequency output power is increased/decreased in a linear manner, if required; and also, any one of operations as to a cooling means, an illumination means, a food mounting means, and a ventilation means is stopped, or is carried out under low power when the maximum higher frequency power is outputted.
As a consequence, highest-speed heat-cooking operation by outputting the maximum high frequency power can be realized, the cooking sequence capable of conducting the optimum cooking performance can be realized, and the high frequency output power can be effectively supplied.
A high frequency heating apparatus of the present invention, is featured by that a supply of electric power by a high frequency heating apparatus equipped with an oven hood is carried out by a high frequency power control means constituted by a semiconductor element. As a result, a weight of a power supply apparatus having a large weight ratio can be largely reduced. As indicated in FIG. 8, this high frequency heating apparatus can be easily installed even on a high-place mounting wall plane located above another heat-cooking apparatus, as shown in FIG. 8 in which the high frequency heating apparatus can be hardly installed. In addition, since the weight balance is better, the appliance can be fixed under stable condition, so that safety characteristics thereof can be largely improved.
The invention is featured by that while the power supply apparatus of the high frequency heating apparatus equipped with the oven hood, is realized by a high frequency power control means made of a semiconductor element, since a time limiting element is provided with this power control means, the linear heating output power which is required to cook the object to be heated can be supplied for a necessary time duration, so that optimum cooking performance can be realized.
As represented in FIG. 9 where the effects of the present invention are compared with those of the prior art, the invention is featured by that the supply of the electric power of the high frequency heating apparatus equipped with the oven hood is realized by a high frequency power control means made of a semiconductor element. As a result, since the maximum high frequency electric power can be derived within the range where this maximum high frequency electric power does not exceed the upper limit value of the power consumption as the entire appliance, such electric power control operations can be carried out. That is, when the operations of the ventilation means and the illumination means are stopped, the high frequency heating power up to the upper limit value can be derived. Conversely, when the operations of the ventilation means and the illumination means are carried out, the high frequency heating power can be maintained within the upper limit value of the power consumption of the entire appliance. Thus, the maximum allowable heating power can be controlled within the range where this maximum allowable heating power does not exceed the upper limit value of the power consumption as the entire appliance, if required.
Also, in order to prevent an overheat break down phenomenon of the semiconductor element provided within the heating apparatus whose self-heating amount is the highest value, a temperature of cooling wind thereof is sensed. As a result, the high frequency output power is controlled before such a problem happens to occur, so that break down phenomena of the components, smoking of these components, and firing of these components may also be prevented.
The invention is featured by that while the power supply apparatus of the high frequency heating apparatus equipped with the oven hood, is realized by a high frequency power control means made of a semiconductor element, maximum high frequency output power higher than the normal high frequency output power is supplied for a constant time period after a supply of electric power is commenced. As a consequence, at a time instant where the self-heating amount of the power supply apparatus is low when the power heating operation is commenced, a heat efficiency can be effectively utilized in a maximum value, and the heating power can be supplied. More specifically, while the use frequency becomes maximum and also the large effect may be achieved, the large time reduction of the light load heat-cooking operation can be realized.
The invention is featured by that while the power supply apparatus of the high frequency heating apparatus equipped with the oven hood, is realized by a high frequency power control means made of a semiconductor element, the maximum high frequency output power is supplied for a constant time period after the heating operation is commenced. As a result, in particular, while the use frequency becomes maximum and also the large effect may be achieved, the large time reduction of the light load heat-cooking operation can be realized.
A high frequency heating apparatus, of the present invention, is featured by such a high frequency heating apparatus equipped with an oven hood, comprising: a heating chamber for entering thereinto/deriving therefrom an object to be heated such as food, an electromagnetic wave radiation unit for radiating electromagnetic waves into the heating chamber; cooling means for cooling the electromagnetic wave radiation unit; first illumination means for illuminating light into the heating chamber; second illumination means for illuminating another heat-cooking apparatus by light, which is installed under a main body of an appliance; food mounting means for mounting thereon the food within the heating chamber and being operated in rotation motion; ventilation means for ventilating gas generated from the another heat-cooking apparatus, which is taken from an air suction portion; and control means for controlling the electromagnetic wave radiation unit, the cooling means, the first and second illumination means, and the food mounting means; wherein: high frequency output power of the electromagnetic wave radiation unit is switched in plural output stages, and when maximum high frequency output power is outputted, any one of operations as to the first and second illumination means, and the food mounting means is stopped, or is carried out under low power. As a result, since the maximum high frequency electric power can be derived within the range where this maximum high frequency electric power does not exceed the upper limit value of the power consumption as the entire appliance, such electric power control operations can be carried out. That is, when the operations of the ventilation means and the illumination means are stopped, the high frequency heating power up to the upper limit value can be derived. Conversely, when the operations of the ventilation means and the illumination means are carried out, the high frequency heating power can be maintained within the upper limit value of the power consumption of the entire appliance. Thus, the maximum allowable heating power can be controlled within the range where this maximum allowable heating power does not exceed the upper limit value of the power consumption as the entire appliance, if required.
A high frequency heating apparatus of the present invention, is featured by that the high frequency heating apparatus is constituted to supply the maximum high frequency output power for a constant time period after the heating operation is commenced. As a consequence, at the time instant where the self-heating amount of the power supply apparatus is low when the power heating operation is commenced, the heat efficiency can be effectively utilized in the maximum value, and the heating power can be supplied. More specifically, while the use frequency becomes maximum and also the large effect may be achieved, the large time reduction of the light load heat-cooking operation can be realized.
A high frequency heating apparatus is featured by that the high frequency heating apparatus is further comprised of: temperature sensing means for sensing a temperature of the electromagnetic wave radiation unit; and the high frequency heating apparatus is constituted by supplying the maximum high frequency output power while the sensed temperature of the electromagnetic wave radiation unit is lower than, or equal to a certain temperature. As a result, since the high frequency power is lowered and the operation of the cooling fan is commenced, the increase in the temperature can be stopped. As a consequence, there is such an effect that the high frequency output power can be effectively supplied in accordance with the reliability of the magnetron.
A high frequency heating apparatus of the present invention, is featured by that the high frequency heating apparatus is further comprised of: detection means for detecting a physical amount (weight, shape, temperature, dielectric constant etc.) of the food, and also for detecting a condition (temperature, humidity, electric field etc.) of the heating chamber; and the high frequency heating apparatus is arranged to supply the maximum high frequency output power in response to a detection output of the detection means. As a consequence, at the time instant where the self-heating amount of the power supply apparatus is low when the power heating operation is commenced, the heat efficiency can be effectively utilized in the maximum value, and the heating power can be supplied. More specifically, while the use frequency becomes maximum and also the large effect may be achieved, the large time reduction of the light load heat-cooking operation can be realized.